From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2E17C7619A for ; Mon, 27 Mar 2023 10:22:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233369AbjC0KWw (ORCPT ); Mon, 27 Mar 2023 06:22:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233597AbjC0KWn (ORCPT ); Mon, 27 Mar 2023 06:22:43 -0400 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 38C165FE8; Mon, 27 Mar 2023 03:22:38 -0700 (PDT) Date: Mon, 27 Mar 2023 12:22:32 +0200 From: Pablo Neira Ayuso To: Igor Artemiev Cc: Jozsef Kadlecsik , Florian Westphal , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [lvc-project] [PATCH] netfilter: nfnetlink: NULL-check skb->dev in __build_packet_message() Message-ID: References: <20230327094116.1763201-1-Igor.A.Artemiev@mcst.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230327094116.1763201-1-Igor.A.Artemiev@mcst.ru> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 27, 2023 at 12:41:16PM +0300, Igor Artemiev wrote: > After having been compared to NULL value at nfnetlink_log.c:560, > pointer 'skb->dev' is dereferenced at nfnetlink_log.c:576. > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > Signed-off-by: Igor Artemiev > --- > net/netfilter/nfnetlink_log.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c > index d97eb280cb2e..2711509eb9a5 100644 > --- a/net/netfilter/nfnetlink_log.c > +++ b/net/netfilter/nfnetlink_log.c > @@ -572,7 +572,7 @@ __build_packet_message(struct nfnl_log_net *log, > } > } > > - if (indev && skb_mac_header_was_set(skb)) { > + if (indev && skb->dev && skb_mac_header_was_set(skb)) { This cannot ever happen, we assume skb->dev is always set on. > if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) || > nla_put_be16(inst->skb, NFULA_HWLEN, > htons(skb->dev->hard_header_len))) > -- > 2.30.2 >